The purpose of the proposed experiments is to examine certain unique organizational and functional characteristics of the input and output systems of the neocerebellum. The individual experiments are designed to produce results which will povide certain insights into the concepts underlying these issues. Specifically, features of both the anatomical organization and physiological action of output projections from the dentate nucleus projecting via the descending branch of the brachium conjunctivum will be studied. Experiments will be directed toward determining which descending pathways are activated by this part of the dentate output system as well as the spinal interactions produced by this proposed dentato-reticulospinal system. Another series of studies will be performed to confirm the existence of a cerebellar nucleocortical projection and to examine its topographical and electrophysiological characteristics. The hypothesis that the dentate nucleus and lateral cerebellar cortex receive afferents activated by ascending spinal systems which do not involve supratentorial structures will also be tested. In addition to examining certain organizational features of this spinoneocerebellar system, part of these studies will be directed toward elucidating features of both temporal and spatial integration occurring in the cerebellar nuclei and cerebellar cortex. Finally, the action of the cerebello-olivary projection will also be investigated with emphasis on examining the patterns of convergence from different cerebellar nuclei to cells in the inferior olive. BIBLIOGRAPHIC REFERENCES: Tolbert, D.L., Bantli, H., and Bloedel, J.R.: The topological organization of the cat cerebellar nucleocortical projection. Anat. Rec., 1977, in press. Bantli, H., and Bloedel, J.R.: Indirect peripheral inputs to the neocerebellum. Proc. Int. Physiol. Soc., 1977, in press.